At Onsrud, "Super Duty" means cast iron. It also means the spindle travels the stationary bridge along the width of the tables while the tables pass underneath the bridge along their short dimension. This design (like our moving gantry design) only uses half of the floor space that a long single moving table design would use. Its design is extremely efficient, shuttling the twin tables for continuous production and 100% cutting time. With this design, the CNC"s table can be loaded and off-loaded without interrupting the cutting and production that is occurring on the other table. Its heavier and thicker cast iron frame tends to naturally absorb or dampen any cutting vibrations. Simply put, cast iron just has a better ability to absorb and dampen cuttingvibrations, while steel tends to amplify and transmit theseoscillations to the rest of the frame. When you arecutting man-made materials most of the time, aheavy, tubular steel frame, like our Panel ProSeries is acceptable. But, if you intend to cutprimarily solid wood or non-ferrous metals, whichcreates significantly more vibrations, then you willdefinitely want the additional dampening ability of a castiron frame, such as the Onsrud "Super Duty" Series. You willquickly find that the cast iron frame design will not only contribute tothe overall weight, mass, and rigidity of the machine, but will also promote fasterfeed rates, better finishes, longer tool life and less maintenance. A cast iron framedesign will usually cut much deeper per pass and machine much faster while maintaininga better finish. It will simply out-produce all other designs and make more money foryou in the process. Take a look at the most expensive and productive model offered byany "high-end" CNC router manufacturer. It will almost always use the same cast iron,Twin Table, Fixed Frame design as the C.R. Onsrud "Super-Duty" series routers. *Call today for a quote